Torsional Vibration Sensor Using Magnetic Field Modulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for measuring torsional vibrations in rotating machinery are limited by their complexity, reliability, and applicability, often requiring significant modifications to the machine, and are not commonly used due to difficulties in accurate and reliable signal acquisition, especially in field troubleshooting scenarios.
Innovation Solution
A torsional vibration sensor system that includes a support structure attachable to a rotating machine element, equipped with a sensor array comprising accelerometers to measure tangential and radial accelerations, and a data processor to estimate torsional vibration amplitude by calculating the ratio of these accelerations, allowing for wireless data transmission and easy installation on a short length of exposed shaft.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If strain gauges are bonded to the rotating shaft to measure torsional vibration, then measurement accuracy is improved, but device complexity and installation time increase significantly
Solution Approach 1:
The patent replaces the mechanical strain gauge system with a magnetic field-based measurement system. A magnetic transducer generates a carrier signal that is modulated by the torsional vibration of the shaft, eliminating the need for mechanical strain gauges, bonding agents, and complex signal transfer mechanisms while achieving accurate torsional vibration measurement
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the rotating shaft and the stationary transducer. The magnetic transducer on the shaft modulates a carrier signal through magnetic field interactions, serving as a mediator that transfers vibration information from the rotating shaft to the stationary measurement system without requiring direct mechanical connection or complex signal transfer components
2Measurement precision
If strain gauges are installed on the shaft, then torsional vibration can be measured, but reliability decreases due to environmental deterioration
Solution Approach 1:
The patent replaces the mechanical strain gauge system vulnerable to environmental conditions with a magnetic field-based system. The magnetic transducer and carrier signal modulation approach eliminates bonding agents that deteriorate and protects against temperature and chemical effects, improving reliability while maintaining measurement capability
Solution Approach 2:
The patent uses a self-generating carrier signal from the shaft's own magnetic field rather than relying on fragile bonded strain gauges. This approach uses the shaft's inherent magnetic properties as a reusable, durable signal source that is not susceptible to environmental deterioration
3Measurement precision
If a torsiograph with toothed wheel is used, then torsional vibration measurement is achieved, but the device requires exposed shaft end and does not respond at low frequencies
Solution Approach 1:
The patent creates a universal measurement system that can be applied to various shaft configurations (with or without exposed ends, with different gear arrangements) by using magnetic field interaction that does not require mechanical attachment points. The system responds across a wide frequency range including low frequencies by using the shaft's inherent magnetic field rather than mechanical toothed wheels
4Measurement precision
If commercially available torsional vibration systems are used, then measurement capability is provided, but significant modifications to the rotating machine are required
Solution Approach 1:
The patent makes the shaft itself serve the measurement function by using its inherent magnetic field to generate the carrier signal. This self-service approach eliminates the need for external modification of the shaft or machine, as the shaft's own magnetic properties are utilized for measurement
Solution Approach 2:
The patent replaces mechanical modification approaches with a magnetic field-based system that requires no drilling, machining, or structural changes to the shaft. The magnetic transducer can be mounted on the shaft surface without altering the shaft's mechanical integrity or requiring exposed ends
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate measurement of both steady-state and transient torsional vibrations, applicable to drive trains with or without gears, and can be quickly installed in the field, providing reliable data for diagnostics and maintenance without compromising machine safety or reliability.
Implementation Method 1
A magnetic transducer on the shaft generates a carrier signal
Data Source
AI summary
A device is disclosed for measuring torsional vibrations superimposed on rotating equipment such as a shaft. The device may be fastened to a rotating shaft by a collar and includes a sensor array comprising two or more accelerometers measuring the radial acceleration of the sensor array and the tangential acceleration of the sensor array. The gravitational component of the accelerometer signals is identified either by isolation in one of the signals, or by comparing two or more signals. From the tangential and radial acceleration signals, a torsional vibration amplitude is calculated from the ratio of the tangential acceleration and the radial acceleration. The radial acceleration is further used to determine the average velocity of the sensor array. The tangential acceleration may further be integrated to obtain the angular velocity of the sensor array, or further integrated to obtain the angle rotated through.